Circuit breaker



oct. 25, 193s. K, wULsTE-N 2,134,593

CIRCUIT BREAKER TTORNEY K. WULSTEN CIRCUIT BREAKER Oct. 25, 1938.

Filed Feb 2l. 1934 5 Sheets-Sheet 2 n am mkv RA N .O wu w H Y UB K m of N T m M Patented on. 25, 193sV UNITED STATES PATENT OFFICE v i 2,134,593 y i cmom'r nimma Kurt Wulsten, Berlin-Charlottenburg, Germany,

assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation oi Pennsylvania Application February 21, 1934, Serial No. 712,344

In' Germany February 25, 1933 34 claims. (ci. v17a-294) My invention relates .particularly to circuit breakers of the type used for controlling lighting aliid moderate power distribution or network circ ts.

Circuit breakers for this type of service present a rather complex` problem tothe electrical art. Ordinarily, they are used in homes or factories and must, therefore, be positive in operation and absolutely safe. Preferably the breakers are quick-make and.V quick-break to prevent circuit disturbances or prolonged arcing; the trip devices used with the breakers must be reliable and accurate in operation and must cause the opening of the controlled circuit irrespective of the position of theoperating member; and in addition the operating mechanism and the trip device should be entirely resettable after each opening of the circuit as a result ofthe operation of the trip device by movement of the operating member. As against these operational requirements, a commercially successful breaker must be ylow in cost, due to the large number used in even a moderately sized building or factory, and due to the fact that the devices compete directly with the older fuse and separate switch combination.

The principal object of my invention is, therefore, the provision of an improved circuit breaker of the above described type that shall satisfactorily meet all present day operational requirements, and that shall at the same time be low in cost.

This object of my invention is accomplished through the provision of an improved operating mechanism for actuating the circuit breaker contacts and through the provision of an improved trip device which coperates with the mechanism to secure the desired operation of the circuit breaker.

The operating mechanism of my invention 4utilizes a pair of toggle links and a manually movable operating member for moving the contacts to the open and to the closed-circuit position. In contrast to the usual arrangementof toggle operating linkages, the line of action of the tog- .gieis nearly straight when the breaker is open -and is substantially bent when the breaker is closed. This arrangement necessitates the application of a` large force to the operating member in order to initiate movement of the contacts` toward the closed-circuit position. And, since the component of force which causes the movement of the contact members toward the closed circuit position progressively increases (due to the bending of1-the toggle) as the closing operation progresses, the contacts are eiectively closed at high speed without the use of an overcenter spring. Moreover, since the toggle linkage is bent when the breaker is in the closed circuit position, it is possible to secure a much more rapid opening of the circuit ybreaker contacts 5 than has been heretofore possible, due to the fact that it is not necessary to move the knee of the toggle through the overcenter or extended position when eecting the opening of the breaker.

To support the toggle linkage so that the `opera- 19 tion of the trip device shall cause the automatic opening of the circuit breaker, irrespective of the position of the operating member, I provide a second toggle linkage, which in the preferred form comprises a pair of pivotally joined link meml5 bers. This supporting linkage is disposed intermediate the operating linkage and the trip device and is adapted to be substantially straight when the breaker is in the closed circuit position in order to minimize the forces which must be bal- 20 anced by the trip device.

In the improved trip device which is utilized in this embodiment lof my invention, I provide a single trip bar which is actuable by any one of a plurality of electroresponsive tripping elements. 25 In order to meet the increasingly severe requirements of the type of service for which these breakers are intended, I provide one or more electromagnetic tripping elements and one thermally responsive tripping element, each of which is en'\ 30 ergized in response to the current flowing through one of the poles of the breaker. Each of the tripping elements is individually capable of causing the operation of the trip device on the occurrence of predetermined overload conditions 35 which are diierent from the predetermined overload conditions which cause the operation of the other devices. It is thus possible to secure protection over any range of requirements which might be encountered inordinary service. A11 of the 40 several tripping elements directly engage, or are lin part supported upon, the single trip bar, and by virtue of this arangement a substantial reduction in the cost of the apparatus is eected. y

The novel features of my invention and the preferred method of embodying those features into a commercial type circuit breaker will be made more apparent by reference to the following description and drawings, wherein- Figure 1 is an elevational view, partially in section, of a two-pole circuit breaker embodyingthe principal features of my invention,

Fig. 2 is a front elevational view of the circuit breaker shown in Figure 1. The cover has been removed in 'order to more clearly illustrate the structure features involved. Y

Fig. 3 is a fragmentary view showing the operating mechanism and one of the pairs of separable contacts in the normal open-circuit position,

Fig. 4 is a view similar to Fig. 3 showing the operating mechanism and the contacts in the closed-circuit position,

Fig 5 is a view similar to Figs. 3 and 4 showing operating mechanism and contacts in the tripped position,

Fig. 6 is a fragmentary view partially in section showing the features of one of the electromagnetic Jtripping elements,

Fig. 'i is a fragmentary perspective view showing the features of the trip bar and certain of the tripping elements,

Fig. 8 is a schematic view showing the connections of the circuit breaker and the tripping elements,

Fig. 9 is a schematic view showing the electrical connections of the circuit breaker and the controlled apparatus arranged for protection against ground faults,

Fig. 10 is aview of the circuit breaker taken along the line X-X of Fig. i,

Fig. l1 is a. sectional view on the line XI-XI of Fig. l,

Fig. l2 is a fragmentary view, partially in section, showing the features of the combined blowout and trip coiis, and

Fig. 13 is a fragmentary view, partially in section, on the line XIII-XIII of Fig. l2.

The circuit breaker shown in the drawings comprises generally a base i of molded insulating material upon which are mounted a pair of terminal contacts 3 and 5 for connection with the line side of the supply circuit, a pair of stationarycontact members 1, a pair of movable contact members S for cooperating therewith to open and close the circuit, a toggle link operating mechanism Il for moving the breaker to the open and the closed circuit position, a pair of blow-out coils I3 for moving the arc established incident to the opening of the controlled circuit into suitable arc chutes I5, a trip device I1 which includes a plurality of magnetically responsive tripping elements and a plurality of thermally responsive tripping elements, and a second pair of terminals I9 and 2i for connecting the breaker to the load side of the circuit. A suitable cover 23, also of molded insulating material, is provided for enclosing the moving parts of the breaker.

The stationary contacts 1 are each formed from a suitably bent strip of conducting material which is rigidly supported on the base I by means such as a screw fastening or the like. The' movable contact members 9 are each supported upon the base I through .the agency of a resilient support member 25. One end of each of these support members 25 is electrically and mechanically connected to the associated contact member 9 by means of a screw 21, to permit easy replacement of the moving contact members, and the other end is supported upon the base I and is at the same time connected to the terminal 28 of girlie of the blow-out coils I3 by a screw fastening Each of the blow-out coils I3 is Wound in the usual manner about a core member 33 which is shown particularly in Figs. l2 and 13. Each of these core members 33 is provided with two pairs of pole pieces 35 and 31. The upper pair of pole .coils I3 is connected by means of a bolt 4I to the terminal 43 of one of the energizing coils 45 for the magnetically responsive tripping device shown particularly in Figure 6. The other terminal 41 of each of the energizing coils 45 is connected by suitable means to the terminal 49 of one of the bimetallic thermally responsive tripping elements 5I, shown particularly in Fig. 1. The other terminal 53 of each of the bimetallic tripping elements 5| is connected to one of the load terminals of the breaker by means ofa strip of conducting material 55 and suitable screw fastenings 51.

The electrical circuit for each of the poles is thus seen to be comparatively direct. Beginning with the line terminal 5, the current flows progressively through the stationary contact 1, the moving contact 9, the supporting strip 25 therefor, the blow-out coil I3 and thence the energizing coil 45 for the electromagnetic tripping element, and the U-shaped bimetallic member 5I, to the line terminal ZI.

The operating mechanism II for moving the contacts 9 to the open and to the closed-circuitposition is entirely supported upon a U-shaped frame member 59 which is rigidly aiiixed to the base I. It includes an operating member 6I having aV knob 63 of insulating material which is adapted to cooperate with a suitable guide opening 65 in one portion of the mechanism frame, and a guide pin 61 which cooperates with a second suitably proportioned opening 69 for defining the path of movement of the operating member. Both of the moving contact members 9 are biased to the open circuit position at all times by virtue of the resiliency of their support members 25, and in order to actuate the breaker contacts, a pivotally supported insulating member 1I is provided. This member has three projections 13, and 11 formed integrally therewith. 'Iwo of these (13 and 15) serve to engage the flexible supports 25 for the moving contacts 9 to permit normal operation of the breaker, and the third (11) serves as one of the links of the toggle operating mechanism. The other link of the toggle operating linkage comprises a fiat link member 19 pivotally joined at one end to the projection 11 and pivotally joined at the other end to the upper link 8| of the toggle support linkage.

The operating member 6I engages the Operating toggle linkage through a slot 83 which is adapted to slidably engage the pivot pin 85 which joins theoperating and support linkages. By virtue of this slot and pin connection, it is possible for the trip device I1 to cause the opening of the breaker irrespective of the position of the operating member` The toggle support linkage comprises the upper link 8|, previously.mentioned, and a second link member 81 formed in the shape of a bell crank lever. The apex of this bell crank lever 81 is pivotally joined to the upper toggle link 8| by the knee pivot pin 89, and one of the side portions is pivotally supported on a pin 9| which projects outwardly from the frame 59 of the operating mechanism. The end 93 of the other side portion of the bell crank link `81 is ,the other end is provided with a member |23 adapted to be engaged by the movable end |24 of adapted. to engage a suitable latching member 95 forming a part of the trip bar 50.

In order to facilitate the opening of the breaker, a spring 91 is provided for biasing the operating member 6|. to the open circuit position.

This spring 91 valso Lserves the function of automatically restoring the several parts of the breaker and the trip device to an operative position following an opening of the breaker resulting from the operation of the trip device. The force exerted by the spring 91 is incapable of opening the breaker under normal operating conditions.

'I'he trip device |1 comprises, as mentioned above, a single, pivotally supported trip bar 50, having a latch member 95 at one end thereof for cooperating with the support toggle linkage to permit manual operation of the breaker, and a plurality of tripping elements for causing the breaker to open automatically upon the occurrence of predetermined conditions in the controlled circuit. A U-shaped saddle member 99 is supported upon the central portion of the trip bar 50 and is rigidly aflixed thereto, as is shown in Fig. 7. Ailixed to the base portion of thisv saddle are a pair of rigid metal strips 0| each of which serves to support one of the iron armatures 52, at its upper end. The armatures 52 are positioned, in the assembled breaker, adjacent the pole pieces 31 which are energized by 'the combination blow-out and trip coils I3, and are each individually biased out of engagement with those pole pieces 31 by means of suitable coil springs |03 retained within recesses |05 formed in the base\|. In addition to the magnetically responsive tripping elements formed by the armatures 52, and the energizing means therefor, the trip device includes a second electromagneticallyresponsive tripping means which includes a separate electromagnetically responsive tripping element for each of the two poles of the breaker.

This second tripping means is shown particularly in Fig. .6 and is normally energized by either of the coils 45, each of which is connected in series withl the circuit controlled by one'of the pairs of separablecontacts. Either of the two coils 45 is capable of attracting an armature |01, upon the occurrence of predetermined overload conditions, to cause the operation of the trip device. The tripping coils 45 are supported -upon a portion of the frame 59 utilized for supporting the operating mechanism, and are each adapted to energize a suitable core member |09 which cooperates with the movable armature |01. The armature |01 is formed from a tubular means of magnetic material and is open at the lower end.

During the normal operation of the device, the armature |01`moves within a guide tube of insulating material disposed within the attracting coils 45. This tube is provided with a slot ||3 within which a projection ||5 formed integral with the armature moves'to cause rotation of the trip bar 50 during the tripping operation. A screw ||1 is provided for controlling the distance separating the armature |01 and the core |09 of the attracting means therefor, in order to permit adjustment of the tripping point.

' The trip bar 50 is provided with" an L-shaped arm ||9 rigidly aftlxedthereto at its midpoint. The upper end |2| of this arm is adapted to engage the projection ||5 on the armature |01 of the magnetically responsive tripping means, and

each of the thermally responsive tripping elements 5|.

It will thus be seen that the trip device is 5 provided with three electro-responsive tripping elements for each of the two poles of the breaker. By a proper selection of thenumber of turns in the blow-out coils I3 and the number of turns in the coils 45 `used for energizing the other l0 magneticallyv responsive tripping means, it is possible to secure protection of the controlled apparatus over a wide range of current value. All of the magnetically responsive tripping elements are individually operable to cause the opening of l5 the Abreaker immediately following the occurrence of predetermined conditions. Each of the thermally responsive tripping elements 5|, however, is operable to cause the actuation of the trip device only after a time delay which is in- 20 versely proportional to vthe current iiowing therethrough.

'I'he operating mechanism and the contacts of .the circuit breaker are shown in the normal openclrcuit position in Fig. 3. To close the contacts 25 manually, a force lis applied to the operating member in thedirection toward the base. By virtue of the fact that the knee pivot pin |25 of the operating toggle is only a short distance from the center line of the toggle (the line connecting 30 the pin and the pivotal support for the contact actuating member 1|) only a very small component of this force is effective to cause movement of the contacts from the open-circuit to the closed-circuit position. Thus, in order to 35 close the breaker, it is necessary to apply a very considerable force to the operating member 6|. However, as soon as movement is initiated, the effective component of the motion producing force increases at a very rapid rate, and since it 40 is substantially impossible to prevent the hand from following the operating member at least a short distance, the contactsare closed with what is substantially a snap action. 'I'he moving parts of the operating mechanism then take 45 the position shown in Figni. y

During the circuit-closing operation, the supl port linkage moves from the bent position shown in Fig. 3 to a substantially straight position as shown in Fig. 4. 'I'he support linkage is 50 thus able to balance the large reaction force which may be transmittedY through the operating mechanism by a very small force. This arrangement reduces to minimum the force which must be supplied by the tripping device I1 and thereby 55 permits the securing of a maximum 'of sensitivity in that device. When in the closed-circuit position, the support linkage is always in the overcenter position, thereby assuring that therelease of the end 93 of the bell crank lever 81 by the G0 trip device |1 .will positively effect the opening of the breaker.

'Upon the occurrence of an overload in the circuit controlled by either of the poles of the 'breaker which is of suicient magnitude and du- (35 ration to caus' the actuation of any one of the three tripping elements, the trip bar 50 is rotated. in a clockwise direction. This rotation causes the eccentrically mounted latching member 95 to disengage .the end 493 of the bell crank lever 70 81 and in so'doing causes the support linkage to become incapable of holding the operating linkage in the closed circuit position. The moving parts of the breaker then move automatically to the position shown in Fig. 5, the slot and pin 75 .connection intermediate the operating member and the operating handle making it possible for the tripdevice to cause the automatic opening of the breaker irrespective of the position of that member. Moreover, since the operating linkage isr bent very considerably when the breaker is in the closed circuit position, any movement of that linkage which may be produced by a release of its supporting means serves to cause the opening oi the breaker contacts at the maximum possible speed.

The contacts may be opened manually by pulling the operating member 6| away from the base. This method of operation is not desirable, however, because of the fact that it has a tendency to cause delayed opening of the contacts. To prevent such delayed opening, I provide a slidable member |21 having an insulating button |29 which projects through the cover 23 of the circuit breaker for directly engaging the trip bar 56 to cause the rotation of Athat member, and thereby effect the lopening of the breaker exactly as described above. The body portion of the slidable member |21 engages a suitable guide opening |3| in the frame 59 and is positioned thereon through the engagement of a slotted opening |33 with the pin 9|. The right-hand end (Fig. l) of the member |21 has suitable means for engaging the trip bar D to cause it to rotate to the tripped position.

As soon as the contacts have moved to the open-circuit position following the actuation of the trip device i1, the spring 91 moves the operating member ,6| to the normal open-circuit position and in eiecting this movement causes the support linkage to be moved from the position shown in Fig. 5 to the position shown in Fig. 3.

The opening of the circuit effects the removal of the overload condition from the breaker, and the trip bar Eil is `then free to move under the action oi the biasing springs 03 to the-untripped position, in which position the end 93 of the bell crank lever t1 reengages the latching member 95 so as to permit the supporting linkage to hold the operating linkage in the closed circuit position.

For certain applications it is desirable that the circuit breaker shall open the circuit immediately upon the occurrence of a breakdown of the insulation within the controlled equipments With the breaker of my invention it is very simple to include protection against this condition merely through the provision of an extra tripping coil and a simple switching equipment. The electrical connections for a circuit of this type are shown in Fig. 9 wherein the numerals 3, 5, 19 and 21 represent *the terminals of the breaker, and the numerals 1 and 9 represent the separable contacts. Essentially, this device comprises nothing more than an extra coil |35 (Fig. 6) adapted to attract the armature |01 forming a part of the previously described magnetically responsive tripping means, a means which includes the terminals |31 and |39 for connecting that coil into an electrical circuit, and a switching means |4| (shown particularly in Fig. 11) for permitting the testing of the coil.

The terminal |45 of the coil |35 is directly connected to the breaker terminal |31, and the other terminal |41 of the coil is connected to a double arm lever |49 whichis supported on a pin |5|. One arm of the lever |49 is provided with a lateral lug |53 which engages the terminal member |39 while the other arm of the lever carrles a contact plate |55. Thus when the breaker is in the normal open circuit position, the coll |35 is directly connected to the terminals |31 and |39. A resistance rod |51 of a carbonaceous or like material is positioned within a suitable guide clamp |59 amxed to the base so that it may be slidably moved .and is used as a testing resistance. The end |60 of this rod |51 which is normally disposed a short distance away from the plate |55 is tipped with metal, and the other end is provided with an annular metal member |6| normally pressed against the contact member |62 which is electrically connected to the terminal I9, the rod |51 being held in this position by a biasing spring |63.

A member |65 which is slidably supported on the frame 59 is provided for actuating the switching lever |49. If pressure is exerted on the lnsulating knob |61 aiiixed to the upper portion of this member |65 the lug portion |53 (Fig. 10) of the double arm lever |49 will be caused to disengage the terminal |39. The plate portion |55 of the lever |49 will then engage the end |66 of the resistance rod |51, thereby connecting one end of the coil |35 to the circuit controlled by one of the poles of the breaker, the resistance element |51 being in series with the coil. Further pressure on the insulating knob |61 will cause the lever |49 to enect the disengagement of the annular member |6| from the contact member |62 connected to the terminal I9, and subsequently will cause the annular member |6| to engage the conducting member |63 normally electrically connected to the terminal 2| of the breaker.

In the circuit shown in Fig. 9, the terminal |39 or' the special tripping .device is normally connected to the ungrounded frame of a piece of 'electrical equipment as indicated at M. The

other terminal grounded at G.

Upon the breakdown of the insulation between the frame of the device M and the current carrying conductors thereof, a current will be caused to ow through the coil |35 which is capable of causing the operation of the trip device |1, thereby opening the breaker. The selective means for connecting the coil |35 in series with either pole of the breaker is provided for testing the device to show that the fault tripping apparatus is in an operative condition and that the electrical circuit is intact. It is necessary that it be possible to connect the coil |35 to either of the two poles of the breaker, because the breaker may be used on a direct-current circuit having one side thereof grounded. On an alternating-current circuit having a grounded neutral it is of course necessary to connect the coil to only one of the two phases in order to test the device.

From the foregoing, it will be seen that I have provided an improved circuit interrupter which utilizes an extremely simple form of operating mechanism and trip device. The operating mechanism of my improved breaker is capable of opening and closing the circuits at high speed without requiring the use of an over-center operating spring, and the trip device is capable of causing the opening of the breaker irrespective of theposition of the operating member. The improved operation of the device results, at least in part, from the novel form and arrangement of the operating and support linkages, and the arrangement of these linkages is believed to be an important feature of my invention.

The trip device which, in conjunction with the improved operating mechanism disclosed, accom- |31 of the testing device is pllshes the objects of my invention, is much simpier than the devices heretoforey known in the art. It comprises a single pivotally supported trip bar which is operable by any of a plurality of electro-responsive elements. In addition tothe fact that my improved trip device utilizes merely a single trip bar that bar is employed for supporting the armature of at least one of the electro-responsive tripping elements. f

Another novel feature of my invention is the provision of means for causing the opening of the breaker upon a ,failureof theinsulation in an ungrounded piece of electrical equipment and the combination with that means of means for testing the operation thereof.

In addition to the above features which are capable of wide adaptations to circuit breakers generally, I have disclosed certain structural 'details which are of particular value in carrying out the objects of my invention as pointed out ,in the appended claims.

While in accordance with the patent statutes I have disclosed the foregoing details of a preferred embodiment of my invention, it is to be understood that many of these detailsare merely illustrative and that variations in their precise form will be both desirable and necessary in certain applications. I desire, therefore, that the language of the accompanying claims shall be accorded the broadest construction and that my invention shall be limited only by what isv expressly stated therein and by the prior art.

I :claim as my invention:

1. In a 4circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving'said contact members to the open and to the closed circuit position, and a trip device operable upon the occurrence of predetermined conditions to cause said actuating means to automatically move said contact means to the open circuit position, said actuating means including a toggle linkage for operatively engaging said contact means, and a second toggle linkage intermediate said first toggle linkage and said trip device for supporting said first toggle linkage,` said first toggle linkage being substantially straight when said interrupter is in the open circuit position and being bent at the knee thereof when said interrupter is in the closed circuit position to facilitate rapid opening of the controlled circuit, said second toggle linkage being substantially straight when said interrupter is in the closed-circuit position.

2. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means including an operating member for moving said contact members `to the open and to the closed-circuit position, and a trip device operable upon the occurrence of predetermined conditions to cause said actuating means to automatically move said contact means to the opencircuit position, said actuating means including a toggle linkage intermediate said operating member and said contact means, and a support for said toggle linkage which comprises a second toggle linkage, one end of which operatively engages said trip device, said first toggle linkage being substantially straight when said interrupter is in the open-circuit position and being bent at the knee thereof when Isaid interrupter is in the closedcircuit position to facilitate rapid opening of the controlled circuit upon the actuation of said trip device, said second toggle linkage being substantially straight when said interrupterlis in the closed-circuit position in order 'to minimize the tripping force which must be supplied by said trip device, said second toggle linkage collapsing upon the actuation of said trip device and y thereby becoming incapable of holding said rst linkage in the closed-circuit position.

3. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means including an operating member for moving said contact members to the open and to the closed-circuit position, and a trip device operable upon the occurrence of predetermined conditions to cause said actuating means to automatically move said contact means to the opencircuit position, said actuating means including a toggle linkage intermediate said operating member and said contact means, and a'support for said toggle linkage which comprises va second toggle linkage one end of which operatively engages said trip device, said first toggle linkage being substantially straight when said interrupter is in the vopen-circuit position and being bent at the knee thereof when said interrupter is in the closed-circuit position to facilitate rapid opening of the controlled circuit upon the actuation of said trip device, said second toggle linkage being substantially straight when said interrupter is in the closed-circuit position in order to minimize the tripping force which must be supplied by said trip device,'said second toggle linkage collapsing upon the actuation of said trip device and thereby becoming incapable of holding said first linkage in the closed-circuit position irrespective of the position of said operating member.

4. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means including an operating member for moving said contact lmembers to the open and to the closed-circuit position, and a trip device operable upon the occurrence of predetermined conditions to cause said actuating means to automatically move said contact means to the opencircuit position, said:4 actuating means including two pairs of toggle links, one of the said two pairs of toggle links being substantially straight when said interrupter is in the open-circuit position to facilitate rapid closing of the contact means during the circuit-closing operation, the other of the vsaidtwo pairs of toggle links serving as a support for .the first pair of toggle links in order to permit normal operation of said interrupter in response strained in a position where it supports said first pair of toggle links in an operative position by means associated with said trip device.

5. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means including an operating member for moving said contact members to the open and to the closed-circuit position, and a trip device operable upon the occurrence of predetermined conditions to cause said actuating means to automatically move said contact means to the opencircuit position, `irrespective of the position of said operating member, said actuating means including two pairs of toggle links, one of the said two pairs of toggle links being substantially straight when said interrupter is in the opencircuit position to facilitate rapid closing of the contact means during thel circuit-closing operation, the other of the said two pairs of toggle links serving as a support for the yiirst pair of toggle links in order to permit normal operation of said interrupter in response to movement of said operating member, said second pair of toggle links being normally restrained in a position where it supports said first pair of toggle links in an operative position by means associated with said trip device.

6. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means including an operating member for moving said contact members to the open and to the closed-circuit position, means biasing said contact means to the open-circuit position when said interrupter is in the closed-circuit position, and a trip device operable upon the occurrence of a predetermined condition to cause said contact means to be moved to the open-circuit position by said biasing means, said actuatingmeans including a pair of toggle links disposed intermediate said operating member and said contact means, said pair of toggle links being substantially straight when said interrupter is in the open-circuit position to facilitate rapid closing of said contact means during the circuit-closing operation, and support means for said pair of toggle links comprising a second pair of toggle links, said first pair of toggle links being bent at the knee when said interrupter is in the closedcircuit position and 'said second pair of toggle links being substantially straight when said interrupter is in the closed-circuit position.

7. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position including a toggle linkage and an operating member, and an electro-responsive support means for normally holding said toggle linkage in an operative position, said support means becoming incapable of holding said toggle linkage in the closed-circuit position upon the occurrence o! predetermined conditions and thereby causing said actuating means to move said contact means to the open-circuit position, said toggle linkage being operatively connected to said operating member through a slot and pin connection with the slot extending generally perpendicularly to the direction of movement of the operating mem- `ber.

8. In' a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position including a toggle linkage and a manually operable handle having a slot extending generally perpendicularly to its direction of movement, and an electro-responsive support means for normally holding said toggle linkage in an operative position, said support means becoming incapable of holding said toggle linkage in the closed-circuit position upon the occurrence oi' predetermined conditions and thereby causing said actuating means to move said contact means to the open-circuit position, said toggle linkage being operatively connected to said operating handle through a pin in said slot in order that the operation of said electro-responsivesupportmeans shall cause said actuating means to move said contact meansto the open-circuit position irrespective of the position of said operating handle.

9. In a circuit interrupter, a pair of separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position, and a trip device operable to cause said actuating means to automatically move said contact means from the closed-circuit to the opencircuit position; said trip device including a single trip bar movable to cause the operation of said device, and two separate electromagnetic means, each individually responsive to diilerent predetermined electrical conditions in the circuit controlled bysaid interrupter, for moving said trip bar and thereby effecting the operation of said trip device, one of said electromagnetic means including a movable armature entirely supported upon said trip bar, the other of said electromagnetic means including means movable to engage said trip bar to cause the operation of said trip device.

10. In a circuit interrupter, a pair of separable contact means for opening and for closing the circultf actuating means for moving said contact means to the open and to the closed-circuit position, and a trip device operable to cause said actuating means to automatically move said contact means from the closed circuit to the open circuit position, said trip device including a single trip bar movable to cause the operation of said device, an armature entirely supported upon said trip bar, means responsive to the circuit controlled by said pair oi' separable contacts for attracting said armature upon the occurrence of predetermined conditions and thereby causing the operation of said trip device, and a second means likewise responsive to the circuit controlled by said pair of separable contacts for moving said trip bar to cause the operation of said trip device upon the occurrence of other predetermined conditions.

11. In a circuit interrupter, a pair of seperable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position, and a trip device operable to cause said actuating means to automatically move said contact means from the closed-circuit to the open circuit position, said trip device including a single trip bar movable to cause the operation of said device, an armature entirely supported upon said trip bar, means for attracting said armature upon the occurrence of predetermined conditions in the circuit controlled by said interrupter to cause the operation of said trip device, and means for causing the operation of said trip device upon the occurrence of other predetermined conditions in the circuit controlled in vsaid interrupter, said means including a means of bimetallic material having a portion thereof that is movable to cause movement o! said trip bar.

12. In a circuit interrupter, a pair of separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position, and a trip device operable to cause said actuating means to automatically move said contact means from the closed-circuit to the opencircuit position, said trip device including a single, pivotally mounted trip bar that is movable to cause the operation of said trip device, an armature entirely supported upon said trip bar, means l for attracting said armature upon the occurrence of predetermined conditions in the circuit controlled by said pair of separable contacts, to cause the actuation of said trip device, and means for causing the operation of said trip devices upon the occurrence o! other predetermined conditions in the circuit controlled by said pair of separable contacts, said means including a curcontact means for opening and for closing the varmature upon the occurrence of predetermined conditions in the circuit controlled by said pair of separable contacts to cause the actuation of said trip device, and means for causing the operation of said trip device upon the occurrence of other predetermined conditions in the circuit controlled by said pair of separable contacts, said means comprising a substantially U-shaped current carrying member of -bimetallic material having a portion projecting outwardly from the closed end of said U, said portion being movable and being adapted to directly engage said-trip bar to cause the operation of said trip device.

14. In a trip device for a circuit interrupter, a single trip bar movableto cause the actuation of said device, an armature entirely supported upon said trip bar, means for attracting said armature upon the occurrence of predetermined electrical conditions tocause the actuation of said device, and an electro-responsive means including means operable upon the occurrence of other predetermined electrical conditions to cause said trip bar to be moved to a position where it effects the actuation of said trip device.

15. In a multi-pole circuit interrupter, a plurality of pairs of separable contact means'for defining a plurality of poles, actuating means for moving said contact means to open and to close the circuits controlled by said plurality of poles, and a trip device operable to cause said actuating means to automatically move a plurality of said contact means to the open circuit position, said trip device including a single trip bar extending across a plurality of the poles of said interrupter, a plurality of armatures entirely supported upon said trip bar, a plurality of means, each of which is energized in response to the circuit controlled by one of said pairs vof contacts, for attracting each of said armatures individually to cause the actuation of said trip device upon the occurrence of predetermined electrical conditions, and means responsive to diilerent predetermined conditions for moving said single trip bar to cause the actuation o! said trip device.

.16.,In a multi-pole circuit interrupter, a plurality of pairs of separable contact means for deilning a plurality of poles, actuating means for moving said contact means to open and to close the circuits controlled by said plurality of poles,

and a trip device operable tocause said actuating means to automatically move a plurality of said contact means to the open circuit position, said tripdevice including a single trip bar extending across a plurality of the poles of said interrupter, a plurality of armatures entirely supported upon said trip bar, a plurality of means, each of which is energized in response to the circuit controlled by one of said pairs of contacts, for attracting each of said armatures individually to cause the actuation of -said trip device upon the ocpurrence of predetermined electrical conditions, and a plurality of thermally responsive tripping elements each energized in response to the circuit controlled by one of said pairs of contacts, `each of said thermally responsive trippingtelements vincluding means movable upon the occurrence of predetermined conditions in the controlled circuit to directly engage said trip bar and thereby effect the actuation of said trip device.

1'7. In a multi-pole circuit interrupter, a plurality of pairs of separable contact means for defining a plurality of poles, actuating means for moving said contact means to open and to close the circuits controlled by said plurality of poles, and a trip device operable to cause said actuating means to automatically move a plurality of said contact means to the open circuit position,

said trip device including a single trip bar movable tocause the actuation of said device, a plurality oi?4 armatures entirely supported upon said trip bar, a plurality of means, each of which is energized in response to the circuit controlled by one of said pairs of contacts, for attracting each of said armatures individually to cause the actuation of said trip device upon the occurrence ci predetermined conditions, and means operable in response to different predetermined conditions to cause said trip bar to Vbe moved toa position where it effects the actuation of said device.

18. In a multi-pole circuit interrupter, a plurality of pairs of separable contact means for defining a plurality of poles, actuating means ior Y moving said contact means to open and to. close the circuits controlled by said plurality of poles, and a trip device operable to cause said actuating means to automatically move a plurality of said contact means to the open circuit position, said trip device including a single, pivotally supported, trip bar which extends across a plurality of the poles of said interrupter and which is movable from anormal inoperative lposition to an operative position to effect the actuation of'said trip device, a plurality of armatures supported on said trip bar at spaced intervals, a plurality of means, each of which is energizedin response to the circuit controlled by one of said pairs of contacts, for attracting each oi said armatures individually to cause the actuation of said trip device upon the occurrence of predetermined electrical con,- ditions, and means operable in response to diierent predetermined electrical conditions to cause said trip bar to be moved from 'said normal inoperative position to said operative position.

19. In a circuit interrupter comprising a pair of separable contact members, actuatingmeans for normally movingsaid members to the open and to the closed-circuit position, and a trip device operable to cause said actuating means to automatically move said contact members from the closed circuit to theopen-circuit position, said trip device including' a trip member movable upon the occurrence of an overload from a normal inoperative position to an operative position to effect the actuation ofsaid device, the combination of means adapted to detect break-down of insulation in the circuit controlled by the interrupter comprising an electro-responsive device operable to cause said trip member to bemoved from said inoperativcto saidoperative position, and a switching device movable from a normal open circuit position to a closed circuit position to effect the energization of said electro-responsive device.`

20. In a circuit interrupter comprising a pair of separable contact members, actuating means for normally moving said members to the open and to the closed circuit position, and a trip device operable to cause said actuating means to automatically move said contact members from the alsV closed circuit to the open-circuit position, said trip device including a trip bar movable upon the occurrence of an overload from a normal inoperative position to an operative position to effect the actuation of said device, the combination of means adapted to detect break-down of insulation in the circuit controlled by the interrupter comprising an armature movable to cause said trip bar to be moved from said inoperative to said operative position, a coil means for attracting said armature, .and a test switch movable from a normal open circuit position to a closed circuit position to eiect the energization of said coil means.

21. in a multi-pole circuit interrupter, a plurality of. pairs of separable contacts for defining a plurality of poles, actuating means for moving said contact means to open and to close the circuits controlled by said plurality of poles, and a. trip device operable to cause said actuating means to move a plurality of said pairs of separable contacts to the open circuit position, said trip device including a trip bar movable from a normal inoperative to an operative position to eiect the actuation of said device, electro-responsive means operable when energized to cause said trip bar to be moved from said inoperative to said operative position, switching means movable successively from a normal open circuit position to a plurality of 'closed circuit positions to effect the energization of said electro-responsive means, said switching means being operable when moved to said closed circuit positions to connect said coil means successively into the circuit controlled by each of a plurality of the poles of said interrupter.

22. In a multi-pole circuit interrupter, a plurality of pairs of separable contacts for dening a plurality of poles, actuating means for moving said contact means to open and .to close the circuits controlled by said plurality of poles, and a trip device operable to cause said actuating means to move a plurality of said pairs of separable contacts to the open circuit position, said trip device including a trip bar movable from a normal inoperative to an operative position to eiect the actuation of said-device, 'current-carrying, electro-responsive means operable lto cause said trip bar to be moved from said inoperative to said operative position, and a test switch movable successively from a normal open circuit position to a plurality of separate closed circuit positions, the circuit controlled by each of a plurality of the poles of said interruptor being grounded through said current-carrying, electro-responsive means when said test switch is moved to said closed circuit positions.

23. In a multi-pole circuit interrupter, 'a plurality of p airs of separable contacts for deilning a plurality of poles, actuating means for moving said contact means to open and to close the circuits controlled by said plurality of poles, and a trip device operable to 'cause said actuating means to move a plurality of said pairs of separa'ole contacts to the open circuit position, said trip device including a trip bar movable from a normal inoperative position to an operative position to effect the actuation of said device, an armature movable to cause said trip bar to be moved from said inoperative to said operative position, a coil means for attracting said armature, a test 'switch movable successively from a normal open circuit position to a plurality of separate 'closed circuit positions, the circuit controlled by each of a plurality of the poles of said interrupter being grounded through said enersizing coil when said switch is moved to said closed circuit positions, and means tor limiting the current which shall ow through said coil when said test switch .is in any one o f said closed circuitpositions.

24. In a circuit interrupr, a pair oi separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed circuit position, a trip device operable to cause said actuating means to automatically move said contact means from the closed circuit to the open circuit position, and a closure means which substantially completely encloses said trip device and the other structural elements of said interrupter, said trip device including a. trip member movable from a normal inoperative to an operative position to eil'ect the actuation of said device, electro-responsive means operable when energized to cause said trip member to be moved from said inoperative to said operative position, switching means movable from a normal open circuit position to a closed circuit position to eiect the energization of -said electro-responsive means, and means whereby said switching means may be operated from without said closure.,

25. In a multi-pole circuit interruptor, a. plurality of pairs of separable contact means for dening a plurality oi' poles, actuating means for moving said contact means to open and to close the circuits controlled by said plurality of poles, and a trip device operable to cause said actuating means to automatically move a plurality ot said contact means to the open circuit position, said trip device including a single trip bar movable from a normal inoperative to an operative position to effect the actuation of said device, an amature movable to cause said trip bar tobe moved from said inoperative to said operative position, a'plurality of coil means, each of which is individually capable of attracting said armature to effect the operation of said device, means for energizing each of a plurality of said coil members in accordance with the current conditions in the circuit controlled by one of said plurality of poles, and switching means movable successively from a normal open circuit position to a plurality of closed circuit positions to effect the energization of at least one of said coil means, said switching means being operable when moved to said closed circuit positions to successively ground the circuit controlled by each of a plurality of poles of said interrupter through said l coil means.

26. In a circuit interrupter, a pair of separable contact means for opening and for closing the circuit,`a'ctuating means for moving said contact means to the open and to the closed-circuit position including a trigger biased to move and cause said contact means to move to open-circuit position, and a trip device operable to cause said trigger of said actuating means to automatically move said contact means from the closed 'circuit to the open circuit position, said trip device including a single trip bar having a latch portion normally holding said trigger and movable to cause the release thereof, an armature entirely supported upon said trip bar, means responsive to the circuit controlled by said pair of separable contacts for attracting said armature upon the occurrence ot predetermined 'conditions and thereby causing the operation of said trip device, and a. thermally responsive means likewise responsive to the circuit controlled by said pair o1' separable contacts for moving said trip bar to cause the operation of said trip device upon the occurrence of other predetermined conditions.

27. In a tripA device for a circuit interruptorl having a trigger biased to move and cause opening of the circuit, a single trip bar having a latch portion thereon 'for holding said trigger and movable to cause the release of said trigger, an amature entirely supported upon said trip bar, means'for attracting said armature upon the occurrence of predetermined electrical conditions to cause the actuation of said device, and thermally responsive means operable upon the occur,A

rence of` other predetermined electrical conditions to cause said trip bar to be moved to a positiori where it eifects the actuation of said trip device.

28. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the .closed-circuit position including an operating member anda link connected thereto by a slot and pin connection with the slot extending generally transversely of the direction of movement of the operating member, electro-responsive means normally limiting relative movement between said pin and slot so that movement of said operating member causes said link to move the contact means, and said electroresponsive means being operable to permit move ment between said pin and slot so that said contact means may move to open the circuit Without a corresponding movement of the operating member.

29. In-a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position including an operating member mounted for reciprocating movement and an actuated member 'connected to the operating member through a guide surface extending generally transversely of the direction of the reciprocating movement of the operating member, electro-responsive means normally limiting relative movement between said operating member and said actuated member so that movement of said operating member in one direction causes said actuating member to move the contact means to close the circuit, said electro-responsive means being operable upon the occurrence of a predetermined condition to permit said actuating member to slide along said guide surface and cause movement of said contact means to open the circuit without movement of said operating member, and means for causing movement of said operating member in the opposite direction after movement of said contact means to open the circuit in response to operation of said electro-responsive means.

30. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position including an operating member mounted for reciprocating movement and an actuated member connected to the operating member through a guide surface extending generally transversely of the direction of the reciprocating movement of the operating member, holding means normally- 'rection causes said actuated member to move the contact means to close the circuit, electro-re- -sponsivemeans for releasing said holding means to permit said actuated memberto slide along said guide surface and cause movement of said contact means to open the circuit without requiring movement of said operating member, and

means for thereafter causing movement of said operating member to open circuit position and for automatically resetting said holding means.

3l. In a circuit interrupter, separable contact means for opening and for closing the circuit, actuating means for moving said contact means to the open and to the closed-circuit position including an operating member mounted for reciprocating movement and an actuated member connected to Athe operating member through a guide surface 'extending generally transversely of the direction of the reciprocating movement of thel operating member, holding means normaily limiting relative movement between said operating member and said actuated member so that movement of said operating member in one direction causes said actuated member to move the contact means toV close the circuit, electroresponsive means -for releasing said holding means to permit said actuated member to slide along said guide surface and cause movement of said contact means to open the circuit without requiring movement of -said operating member, a manually operable member for releasing said holding means independently of said electro-responsive means, and means for thereafter causing movement of said operating member to open' circuit position and for automatically resetting said hoiding means so that said contact means may be reclosed by movement of the iirst said operating member.

32. In a multi-pole circuit interrupten-a plurality of pairs of separable contact means for defining a plurality of poles, actuating means .for moving said contact means to open and to close the circuits controlled by said plurality of poles and including a trigger biased to move and cause said contact means to move to open-circuit position, and a trip device operable to cause said trigger of said actuating means to automatically move a plurality of said contact means to the open circuit position,said trip device including a. single trip bar having a latch portion normally holding said trigger and movable to cause the release thereof, a plurality of armatures entirely supported upon said trip bar, a plurality of means, each of which is energized in response to the circuit controlled-by one of said pairs of contacts, for attracting each oi said armatures individually to cause the actuation of said trip device and the release of said trigger upon the occurrence of predetermined conditions, and means operable in response to different predetermined conditions to cause said trip bar to. be moved to a position where it eiiects theactuation of said device and the release of said trigger.

33. In a multi-pole circuit interrupter, a plurality of pairs of separable contact means for deiining a plurality of poles, 'actuating' means for. moving said contact means to open and to close the circuits controlled by said plurality of poles and including a trigger biased to move and cause said contact means to move to open-circuit position, a trip device operable to cause said trigger of said actuating means to automatically move a plurality of said contact means to the open circuit.` position, said trip device including a single trip bar having a latch portion normally holding said trigger andk movable to cause the release thereof, said actuating means including a handle member normally movable for opening and closing all of said contact means, a plurality oi" armatures entirely supported upon said trip bar, a plurality'ofmeans, eachof which is energized in response to the circuit controlled by one of said pairs of contacts, for attracting each of said armatures individually to cause the actuation oi said trip device and the release of said trigger upon the occurrence of predetermined conditions, means operable in response to diiierent predetermined conditions to cause said trip bar to be moved to a position where it effects the actuation of said device and the release of said trigger, and said release of said trigger causing opening of said contact means by said actuating means irrespective of the position in which said handle member may be held. A

34. In a multi-pole circuit inten-opter, a plurality of pairs of separable contact meanstor defining a plurality of poles, actuating means for moving said contact means to open and to close the circuits controlled -by said plurality of poles and including a trigger biased to move and cause said contact means to move to open-circuit position, a trip device operable to cause said trigger of said actuating means to automatically move a plurality of said contact means to the open circuit position, said trip device including a single trip bar having a latch portion normally holding said trigger and movable to cause the release thereof, said actuating means including a handle member normally movable for opening and closing all of said contact means without causing release oi' said trigger by said latch portion, a plurality of armatures entirely` supported upon said trip bar, a plurality of means., each of which is energized in response to the circuit controlled by one of said pairs of contacts, for attracting each of said armatures individually rto cause the actuation of said trip device and the release o! said trigger upon the occurrence of predetermined conditions, means operable in response to different predetermined conditions to causesaid trip bar y to be moved to a position'where it eiiects the actuation of said device and therelease o! said trigger, said release oi said trigger causing opening ot said contact means by saidiactuating means irrespective of the position in which said handle member may be held, and said handle member being operable to return said trigger into engagement with said latch portion after opening of said contact'means.

KURT WUIBTEN. 

